The pairing logic, in depth
“What wine goes with pasta?” has no single answer because “pasta” isn't a flavor - it's a vehicle. The sauce carries everything the wine has to react to: acid, fat, salt, herbs, protein. Once you pair to the sauce, the noodle shape is irrelevant. Tomato sauces are acidic and a little sweet, which is exactly why they demand a high-acid red. Drink a soft, low-acid red with marinara and the wine collapses into something dull and jammy; drink Chianti and both the wine and the sauce light up.
Cream changes the rules completely. Alfredo and carbonara are exercises in fat - butter, cream, egg, hard cheese. Fat wants either acidity to cut it or richness to match it, and a fuller white (oaked Chardonnay, or a richer Italian white) does both better than a red, whose tannin turns chalky against dairy. If you must drink red with a cream sauce, choose something low-tannin and bright like Barbera.
Pesto and oil-based sauces are the green, herbal end of the spectrum. Basil, pine nut, and garlic call for a wine that's also green and herbal - Sauvignon Blanc, Vermentino, a Ligurian white - and crisp enough that the olive oil doesn't coat your palate. A heavy oaked white here tastes clumsy; you want zip. Seafood pastas follow the same logic as seafood generally: light, saline, low-tannin whites.
The money lesson with pasta is that prestige is the wrong axis. A great pasta wine is defined by acidity and freshness, and those are abundant in inexpensive Italian reds and whites. A $60 Napa Cabernet is a worse spaghetti partner than a $13 Chianti, because the Cabernet brings tannin and oak that tomato has no use for. Buy for structure, not for the label.